Have you read the wiki page for the health check? https://github.com/Sonarr/Sonarr/wiki/Health-checks#drone-factory-is-deprecated
The problem with Drone Factory (and why it will be removed) is new users, find it use it then have issues, items stuck in queue, seeding torrents being removed being the top reasons. We understand some people are relying on it, but with the ability to trigger the same functionality through the API, a small script and task scheduler/cron can replace the functionality.
Auto extracting of RARs is still something we plan to do, but it’s not a reason to keep Drone Factory around.
Drone Factory will be removed in v3 of Sonarr, which does not have an ETA, but we want to give ample notice that it will be removed and avoid the common pitfall for new users that set it up.